As observed from the top of a 100 m high light house from the sea-level, the angles of depression of two ships are $30^{o}$ and $45^{o}$ If one ship is exactly behind the other on the same side of the light house, find the distance between the two ships. [Use $\sqrt{3}=1.732$]
Given: Height of the light house$=100\ m$, the angles of depression of two ships are $30^{o}$ and $45^{o}$ and one ship is exactly behind the other on the same side of the light house.
To do: To find the distance between the two ships.
Solution:
Let ships are at distance $x$ from each other
In $\vartriangle APO$
$tan45^{o}=\frac{100}{y}=1$
$\Rightarrow y=100\ m$ ...$( i)$
In $\vartriangle POB$,
$tan30^{o}=\frac{OP}{OB}=\frac{100}{x+y}=\frac{1}{\sqrt{3}}$
$\Rightarrow x+y=100\sqrt{3} $
On subtituting $y=100\ m$ from $( i)$,
$x+100=100\sqrt{3}$
$\Rightarrow x=100(\sqrt{3}-1)$
$\Rightarrow x=100(1.732-1)$
$\Rightarrow x=73.2\ m$
$\therefore$ Ships are $73.2\ meter$ apart.
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